MATHEMATICAL BASED MODEL OF STREPTOMYCES GROWTH ON WOODEN MATERIAL

Abstract

A mathematical model for the growth of filamentous microorganisms has been tested by comparison of model predictions with data on growth of Streptomyces on building wood material. Growth of Streptomyces resulted in movement of filament classes to increasing the size, while shear forces produced mycelial fragments which entered the smallest size class, from which they grew to form further colonies on building surface materials. Quantification of Streptomyces growth in the model is based on the mould index used in the experiments for visual inspection. The model consists of differential equations describing the growth rate of the mould index in different fuctuating conditions including the effect of exposure time, temperature, relative humidity and dry periods. Temperature and humidity conditions favourable for mould growth are presented as a mathematical model. The modified model generated predictions which agreed closely with experimental data on biomass concentration, distribution, number of colonies and colonies radius during their growth on building wood material, thereby supporting the assumptions on which the model was based. The numerical values of the parameters included in the model are fitted for pine and spruce sapwood, but the functional form of the model can be reasoned to be valid also for other wood-based materials. Keywords : streptomycetes, mathematical model, building materials, humidity, temperature